1. Field of the Invention
The present invention relates to a mobile communication system interworked with a PLMN (Public Land Mobile Network) and a wired/wireless private network, and more particularly to an apparatus, method and system for matching subscriber states of a PLMN and subscriber states of a wired/wireless private network by informing the PLMN of the subscriber states associated with the wired/wireless private network in a mobile communication system.
2. Description of the Related Art
Because a public mobile communication network and a private (or local area) mobile communication network are individually implemented, it is difficult for the public and private networks to be interworked with each other. In other words, a conventional mobile communication system can provide either public mobile communication services or private mobile communication services. A subscriber of a mobile communication terminal registered in the public network cannot use the private mobile communication services. Similarly, a subscriber of a mobile communication terminal registered in the private network cannot use the public mobile communication services. Accordingly, a system, which can provide the subscriber of one mobile communication terminal with both the public and private mobile communication services, is seriously needed.
Copending Korean Patent Application Ser. No. 2000-028172 entitled “SYSTEM AND METHOD FOR PROVIDING PUBLIC/PRIVATE MOBILE COMMUNICATION SERVICE”, filed in the Korean Industrial Property Office on May 24, 2000 by Samsung Electronics Co., Ltd. is disclosed as an example of a public and private mobile communication system, which can provide one mobile communication terminal with both public and private mobile communication services.
Hereinafter, an MS is a mobile station being a mobile communication terminal. An MSC, a BSC and a BTS denote a mobile switching center, a base station controller and a base station transceiver subsystem, respectively. A prefix “p” attached to “MS”, “MSC”, “BSC” or “BTS” means “private”. For convenience, the prefix “p” is used to distinguish components of the private network from components of the public network.
Copending Korean Patent Application Ser. No. 2000-060831 entitled “APPARATUS AND METHOD FOR PERFORMING PACKET DATA COMMUNICATION IN LOCAL-AREA RADIO INTERNET”, filed in the Korean Industrial Property Office on Sep. 28, 2000 by Samsung Electronics Co., Ltd. is disclosed as an example of enabling use of a local-area radio internet by applying a wired/wireless mobile communication system to a 3G (3rd generation) network.
As disclosed in Korean Patent Application Ser. No. 2000-060831, a paging signal is transmitted through a path of “MSC->BSC->BTS->MS” in a conventional PLMN rather than an interworking service system in which the public and private networks are interworked, and a paging response message generated by the MS is transmitted through a path of “MS->BTS->BSC->MSC” as a reverse path of the paging signal path.
On the other hand, a wired/wireless communication service system disclosed in Korean Patent Application Ser. No. 2000-060831 transmits a paging signal through a path of “MSC->BSC->pBSC->BTS->MS” and a paging response message generated by the MS for the public and private networks is transmitted through a path of “MS->BTS->pBSC->BSC->MSC” as a reverse path of the paging signal path. Here, the pBSC transparently transmits the paging signal where it is the public-network paging signal and therefore does not affect processing of incoming and outgoing paging signals from and to the public network in a terminal, which is located within a public and private cell area. Accordingly, the private network is compatible with the public network. Further, the BSC for the public network can be directly coupled to the BTS without the use of the pBSC. Where the paging signal from the private network is generated, the processing of the paging signal is controlled within the private network.
When a local-area MS located within the public and private cell area, communicates with another local-area terminal or another terminal through a PBX (another local-area terminal coupled to the PBX or another terminal coupled to a PSTN (Public Switched Telephone Network), which can be coupled to an office line of the PBX) in the wired/wireless mobile communication system, the public network generates a paging signal because the public network recognizes the fact that the corresponding terminal is in an idle state rather than the fact that the corresponding terminal is coupled to a local-area call, where the public network pages the local-area MS. However, when the terminal is coupled to the local-area call, it cannot give any response to the paging signal from the public network. Accordingly, the public network does not identify a current location of a corresponding MS and transmits a second paging signal. There is a problem in that this causes radio resources of the public network to be wasted and cannot enable a caller to exactly recognize a state of a called party. Here, the second paging signal means not only an increase of the number of paging times but also expansion of a paging zone. In other words, the number of BTSs within the paging zone when the second paging signal is transmitted can be increased more than that within the paging zone when a first paging signal is transmitted. Here, the paging zone is previously prescribed. Further, the paging performed in the public network can exceed a predetermined paging range corresponding to the public and private networks.